Max Planck Institute for Nuclear Physics

Many of the details concerning how the world arrived at its current form are still unexplained. Researchers at the Max Planck Institute for Nuclear Physics want to close some of the gaps in our knowledge and thus contribute to an all-encompassing theory for this development. In astroparticle physics they study the structure and the formation history of the universe, which is closely related to the elementary structure of matter. With the H.E.S.S. gamma-ray telescope, for example, they observe the remnants of supernovae. The scientists also investigate the properties of neutrinos, ghost-like elementary particles, and probe the character of dark matter. In the area of quantum dynamics they are interested, for instance, in the interaction of the smallest particles in atomic nuclei, atoms and molecules, which they study in accelerators, storage rings and traps. They also learn more about molecules by controlling simple chemical reactions with intense laser light.

Black holes, pulsars, remnants of exploded stars – these celestial bodies accelerate particles to enormous energies and emit high-energy gamma radiation. The two observatories known as H.E.S.S. and MAGIC, whose construction was supervised by the Max Planck Institutes for Nuclear Physics in Heidelberg and Physics in Munich, make this extreme spectral region accessible.

Neutrinos are particles with seemingly magical powers: the different types are able to transform into one another, and thus have a mass. This discovery earned two scientists the 2015 Nobel Prize for Physics. A quarter of a century ago, these ghostly particles also attracted the attention of researchers at the Max Planck Institute for Nuclear Physics in Heidelberg for the first time. While conducting their Gallex experiment to hunt for them, they looked deep into the furnace of the Sun.

If cosmologists are correct, there is a form of matter in the universe that is six times moreabundant than the matter we know. It is invisible, which is why it’s called dark matter.Postulated for the first time 80 years ago, it has yet to be detected directly. Researchers atthe Max Planck Institute for Physics in Munich and the Max Planck Institute for NuclearPhysics in Heidelberg want to solve this cosmic mystery in the next few years.

Earth is subjected to continuous bombardment. At any point in time, somewhere in the depths of the universe, a star explodes or a black hole ejects gigantic gas clouds from the core of a distant galaxy. These aggressive events are heralded by gamma rays, whichtravel straight through the universe and eventually impact on the Earth’s atmosphere. But this is the end of the line – fortunately for all life, as the energy dose would be lethal in the long term. However, the gamma light doesn’t vanish completely into thin air – a lucky break for astronomers, who can then use it to investigate the cosmic messengers. The radiation leaves its traces in a cascade of particles high above the ground. In the process, a large number of elementary particles are created, which generate Cherenkov radiation – blue flashes that last only one billionth of a second and can’t be seen with the naked eye.In order to record this celestial light, researchers built the four H.E.S.S. telescopes in the Khomas Highland in Namibia several years ago – and they are now converting this quartet into a quintet. H.E.S.S. II is the name of the new dish, which our picture shows bathed in moonlight as it stretches upward like a steel pyramid into the night sky. With a diameter of 28 meters, it roughly corresponds to the area of two tennis courts. And this giant weighs in at no fewer than 580 tons; its camera eye alone weighs three tons. The five scouts of the High Energy Stereoscopic System record the blue flashes with all the tricks of the astronomical observation trade. Securing the evidence in the data then leads to the scene of the crime, as it were: to the source of the radiation. Thus, the astronomers at the Max Planck Institute for Nuclear Physics in Heidelberg, which played an important role in the development and design of H.E.S.S. II as well as coordinating the installation work, also play the role of detectives. Their efforts will soon enable us to better understand the cosmic particle catapults, such as supernovae and black holes.

From single molecules to entire planets – all the visible matter surrounding us consists of atoms. In turn all atoms are composed of only three types of particles. Electrons form the atomic shells, protons and neutrons the atomic nuclei. The basis for a better understanding of this atomic structure is the precise knowledge of its properties, such as the masses of the mentioned particles. The world's most accurate measurement of the mass of the proton has now been achieved with an elaborate Penning-trap apparatus [1].

Despite intensive research since more than 60 years, it is still unknown, whether neutrinos are their own antiparticles or not. This would have considerable implications for particle physics and cosmology. The neutrinoless double beta decay could provide the key information. The GERDA experiment is searching this hitherto still undetected decay for the germanium isotope 76Ge. Presently, GERDA is world leading with the strongest suppression of background events and the best energy resolution, thus providing excellent conditions for a future discovery of the decay.

The new x-ray free-electron laser facilities deliver x-ray pulses of unpreceded brilliance, allowing even for an efficient driving of transitions in atomic nuclei. Such control could facilitate in the future the development of new energy storage solutions. Switching roles, nuclei can be used to store and control single x-ray quanta. This mutual control of nuclei and x-ray photons opens new experimental perspectives, with applications that profit from the robustness, penetration depth and especially from the focusability of x-rays.

Using the intense and ultrashort light pulses provided by the free-electron laser FLASH at DESY in Hamburg, it has been possible for the first time to observe fast dynamical processes in individual highly excited molecules as a function of time. By means of the pump-probe technique, where a molecule is excited by a first pulse and subsequently probed by a second delayed pulse, the mechanisms can be uncovered that proceed within a molecule or during its break-up [1]

By comparing the revolution frequencies of antiprotons and negatively charged hydrogen ions in a strong magnetic field, the to date most precise mass comparison could be performed and thus the most precise direct test of the matter/antimatter symmetry with baryons, particles consisting of each three quarks. The result: the charge-to-mass ratios of protons and antiprotons are identical to the eleventh digit.